Acetone is the way to go. As long as the bearing isn’t part plastic (rarely found on yo-yo bearings but it happens) you could leave it soaking in acetone indefinitely. It will cause no damage to the steel bearing.
A shielded bearing has shields on both sides that you can remove with a sewing needle. If you do not remove them you will likely never get all of the old lube and residue, grime, etc. out of the bearing. But be warned they are a nuisance to put back in and easily damaged.
It takes some effort to actually get a bearing all the way clean. It’s never as clean as you think it is. Dirt, dust, micro bits of string, leftover lube, etc. cling to the balls, the cage, and sit in the raceways. Even if you did manage to get it all out those particulates are floating around in the solvent and some of which will go back inside the bearing when you pull it out of the liquid. It can take 2-4 cleanings to get most of it.
For lubing the type of lube you use, how much you apply, and how you apply it can make a massive difference, and is easy to get wrong. I use a sewing needle to apply the lube and put a small amount on a few of the ball bearings.
After cleaning and lubing and using the bearing for several minutes if it starts screaming, and gets responsive, and seems like it wasn’t lubed at all then you need to use more lube. If it goes quiet and responsive then you either used too much or you didn’t play the yo-yo enough to work the lube around the bearing.
Another thing to note is the same bearing can sound different in two different yoyos. I have a couple in my collection that make the same bearing go from barely noticeable to screaming. It’s usually something you shouldn’t have to worry about.